Wrap-around labelling is commonly used in applying a label onto food and beverage containers, as well as other larger diameter containers. Examples of such technology include the apparatus and methods disclosed in U.S. Pat. No. 4,844,760 to Dickey; U.S. Pat. No. 5,091,239 to Przeworski et al.; U.S. Pat. No. 4,735,668 to Hoffmann et al.; U.S. Pat. No. 4,632,721 to Hoffmann et al.; U.S. Pat. No. 4,761,200 to Szeremeta; U.S. Pat. No. 4,724,037 to Olsen; U.S. Pat. No. 4,832,774 to DiFrank et al.; U.S. Pat. No. 4,686,931 to DiFrank et al.; U.S. Pat. No. 4,416,714 to Hoffmann.
The foregoing apparatus and methods disclosed in the above patents typically cannot be used for high quality cylindrical labeling of thin film labels onto small articles, e.g., dry cell batteries, lipstick containers, or lip balm containers for several reasons as follows:
1. Many of the label transport drums, such as disclosed in the '668, '721 and '760 patents include raised portions positioned on the surface of the drum, typically vacuum or other label retaining means, that inhibit smooth transfer of a smaller label onto a smaller cylindrical article such as a dry cell battery.
2. High quality thin film labels require aesthetic seams produced from a predetermined mount of solvent typically applied to the area adjacent the trailing edge of the label moving on the label transport drum to form a high quality, aesthetic seal at the juncture between overlapping leading and trailing edges. Usually the applied label has three areas adjacent the edge portion substantially free of printed matter and ink providing an area for receiving solvent thereon. These areas are free of ink to prevent distortion of graphics. The more conventional solvent application means such as the direct printing by gravure roll disclosed in the '200, '037, and '210 patents, would not provide an even coat of solvent onto the label. Typically the applied solvent would have a more mottled solvent pattern, forming a low quality seam.
3. Typically an adhesive is applied to the area adjacent the leading edge to form an initial tack weld of the label to the article. Often a hot melt adhesive is used, being solid at room temperature, and viscous at elevated temperatures. If applied to thin label material used with smaller articles, e.g., dry cell batteries, it is believed that the label would distort, causing poor label quality on aesthetic seams once applied.
4. Conventional static wiping of solvent onto a label, such as disclosed in the '760 patent, usually smears the solvent, creating a poor aesthetic seam. Static wiping of solvent is useful with larger articles commonly having opaque labels that hide the seam. However, for the more demanding label applications, such as labeling dry cell batteries, the foregoing solvent application systems are inadequate.
As a result of the foregoing drawbacks described above, high quality cylindrical labeling of small cylindrical articles with thin film labels has heretofore required the use of pre-seamed sleeves formed on a continuous basis and applied directly to the article. The use of pre-seamed sleeves is both slow, inefficient, expensive, and distorts graphics, as compared to the more desired wrap-around labeling technology.
It is therefore more desirable to use wrap-around labeling methods and apparatus to transfer small labels directly onto small cylindrical articles.